Pulmonary Part 1 Flashcards
1
Q
What does the respiratory system refer to?
A
the entire system from openings on the surface of the body for gas inhalation/exhalation to the tissue and cellular utilization of O2 and removal CO2
2
Q
Functions of Respiratory System
A
- Provide O2
- Eliminate CO2
- Regulate pH
- Speech
- Defend body against microbes
- Hormonal regulation of body
- Involved in thrombo-embolism
3
Q
Upper Respiratory Tract Anatomy
A
Nasal and oral airway down to vocal cords
4
Q
Functions of upper respiratory tract
A
- provide low resistance pathway
- defend against microbes, toxins, and foreign bodies
- warm and moisten air
- provide for vocalization
5
Q
upper respiratory tract pathology
A
paralysis or loss of sensation in any part of the pharynx can result in dysphasia and/or aspiration (sets you up for pneumonia)
6
Q
what does the lower respiratory tract connect?
A
vocal cords to alveoli
7
Q
two parts of the lower respiratory tract
A
- conducting airway
- acinar or terminal respiratory units
8
Q
What is the conducing airway?
A
Tracheobronchial tree
9
Q
Conducting airway characteristics
A
- not involved in gas exchange
- 16 generations of branching from 1 inch in diameter in trachea to 1 mm in terminal bronchioles
- cartilaginous rings support upper part
- lower part is muscular
10
Q
Acinar or terminal reparatory units
A
alveoli and alveolar ducts
11
Q
parts of the conducting airways
A
trachea and bronchi
12
Q
Trachea
A
- From cricoid to bifurcation
- Deviates to R before bifurcation
- 16 to 20 incomplete cartilaginous rings
- first is thicker & broader, last has carina
13
Q
Bronchi
A
mainstem, secondary, tertiary, 4th, so on
14
Q
Bronchi characteristics
A
- R mainstem is wider and shorter than L
- R leaves trachea at 25 degree angle
- L mainstem bronchus leaves at 40 degree angle (R often involved in aspiration or foreign body obstruction)
15
Q
Parenchyma
A
functional tissue of the lung
16
Q
Superior aspect of the lungs
A
extend 1 inch above level of the middle of the clavicle into the root of the neck
17
Q
Base of the lungs:
A
concave, resting on convex surface of diaphragm
18
Q
Cardiac impression
A
- the indentation for the heart
- more notable on the left secondary to apex
- lines up with 5th ICS and MCL
19
Q
Hilus
A
- entrance/exit of vessels to lung
20
Q
pulmonary ligament
A
extension of the hilus inferiority
21
Q
can you hear the inferior lobe anteriorly?
A
- not really
- you can hear it posteriorly or laterally
22
Q
Parietal Pleura
A
- Serous membranous lining of thoracic cavity
- costovertebral
- diaphragmatic
- cervical
- mediastinal (innervation & vascular supply via intercostal N and vessels)
23
Q
Visceral Pleura
A
- thin serous tissue which is adherent and inseparable from the lung parenchyma
24
Q
where does innervation and vascular supply to the visceral pleura come from?
A
phrenic nerve and bronchial blood supply
25
Pleural Space
- potential space between the layers
- fluid accumulates here in disease states
26
What do segmental bronchi ramify within a segment to form?
- bronchopulmonary segments
- surrounded by CT layer, continuous with visceral pleura
27
Division of the bronchopulmonary unit
– secondary lobule: smaller unit surrounded by CT
– served by lobular bronchiole
– pyramid shaped
– terminal bronchioles ramify forming respiratory
bronchioles
28
Review the bronchial tree on slide 14
29
bronchioles are to the respiratory system what...
arterioles are to the circulatory system
30
What does secondary lobule contain?
–Terminal bronchiole
–Reparatory bronchioles
–Primary lobules
-Alveolar ducts
-Alveolar sacs
31
what are alveoli/primary lobules
terminal respiratory unit containing alveolar ducts & sacs
– 50 primary lobules/secondary lobule
– 300 million alveoli/mature lung
– mean surface area of 143 m2 (large for gas exchange)
32
Type I alveolar cells
provide for gas exchange
33
Type II alveolar cells
- produce surfactant
- Dipalmitoyl lecithin: phospholipid detergent, decreases surface tension
34
Alveolar-capillary septum
- epithelium and endothelium
- very, very thin membranes --> RBC traveling through there, so the gas doesn't have far to go to get through
35
review overview of steps of respiration slide 18
36
Specialized cells within the lung
- Type I alveolar epithelial cells (pneumocytes)
- Type II alveolar cells (granular)
- others: specialized paracrine cells, mucous
producing cells, inflammatory cells, WBC & support cells
37
Type I alveolar epithelial cells (pneumocytes)
walls & septa of sac, squamous, thin & broad
* Function in gas exchange
* cover 93% of alveolar surface
38
Type II alveolar cells (granular)
- produce surfactant
- occupy the corners of the terminal sac
39
4 periods of respiratory system development
1. Pseudoglandular period: 5-17 weeks
2. Canalicular period: 16-25
3. Terminal Sac period: 24th week to birth
4. Alveolar period: years after birth
40
Pseudoglandular Period
5-17 weeks
- secondary bronchi to level of pulmonary segments
41
Canalicular Period
Weeks 16-25
Most of the branching and framework of
respiratory tree occurs:
* pulmonary segments to respiratory bronchioles
* alveolar ducts and beginning of terminal sacs
42
Terminal Sac Period
24th week to birth
– pulmonary alveoli develop
– capillaries and lymphatics
– surfactant is produced at about 28 weeks
43
Alveolar Period
Late fetal period to 5-7 years after birth
– 1/6 to 1/8th of the adult number of pulmonary alveoli are present at birth
– over the next 5 - 7 years pulmonary alveoli mature and come “on line”
44
After Birth:
▪ About 1/3 of the fluid in the lungs of the neonate is squeezed from the lung in birth canal.
▪ During the next few breaths another 1/3 of the fluid is absorbed into the capillaries.
▪ Remaining fluid is drained by lymphatics
45
What two problems does the neonate have in breathing?
* viscosity of the remaining fluid.
* high surface tension
46
what occurs during birth?
During birth, placental gas exchange is disrupted,
resulting in fetal hypoxemia & hypercapnia
47
Neonatal breathing
▪ First breath requires almost 60 mmHg trans-
pleural pressure to open lung
▪ Each successive breath requires less trans-pleural pressure
48
structure of the airways:
- upper regions and conducting airways
- lower regions (terminal & respiratory bronchioles)
49
Upper regions and conducting airway:
– basal lamina sits on smooth muscle
– ability to constrict
50
Lower regions (terminal & respiratory
bronchioles)
– single layered, cuboidal and mostly non-ciliated
– basal lamina on which they sit has bands of
elastin
- provides elastic recoil during exhalation
51
Innervation of the Respiratory System
* Receives sympathetic & parasympathetic
fibers
– Parasympathetic innervation from Vagus Nerve
– Sympathetic from upper sympathetic ganglia
(cardiac plexus)
52
what do both SNS and PNS fibers form?
anterior and posterior plexi
53
Activation of PNS
bronchiolar constriction, dilation of arterioles,
increased glandular secretion
54
Activation of SNS
bronchiolar dilation, vasoconstriction,
decreased glandular secretion
55
what does gas transport include?
lungs, muscles of respiration, upper and lower respiratory tract
56
ventilation
the physical movement of respiratory
gases (CO2 and O2) in & out of the lungs
57
Diffusion
how gas gets across the membranes
58
Perfusion
- the interface between blood and gas
- mismatching of ventilation & perfusion
59
Respiration
all of the above plus the cellular utilization of oxygen
60
Maintenance of Lung Integrity
* Transpulmonary P keeps the lung from collapsing
* Difference in P from inside the alveoli to intrapleural space
* Elastic recoil is the tendency of a tissue to resist stretch & return to pre-stretched shape
61
Compliance
- change in volume/ change in pressure
- ability of a material to deform when subjected to a deforming surface
62
Wall tension or stress (T)
- the tension required to inflate a sphere
63
Law of LaPlace
P = 2T/r, P = pressure & r = radius
– smaller radius sphere requires greater wall tension to remain open
– Small alveoli prone to collapse!
64
Effect of Surfactant
* Surface tension is greater in a smaller alveolus compared to a larger one (Law of Laplace) - air will move into the larger alveoli.
* Surfactant prevents this by decreasing T in the smaller alveoli.
* Sighing/deep breathing stimulates type II cells to make more surfactant
65
Surfactant
-- Dipalmitoylphospatidylcholine:
– non-polar end (tail)
– polar end (head) dissolves in the surface film of water while the non-polar ends bind the actual alveolar surface, reducing surface tension
66
What does constant-volume breathing allow?
surfactant to equilibrate between alveoli, diminishing effectiveness
67
Resistance to Gas Flow - Low rate of Flow
Laminar Flow: P = flow rate x c
68
Resistance to Gas Flow - High rate of flow
Turbulence: P = flow rate x c
69
Effect of volume
As lung V increases, the
radius of the smallest airways increases, decreasing resistance
70
Normal motion of chest wall:
he chest rises slightly (1-1/2 inches), the diaphragm descends and the stomach moves out in normal quiet breathing
71
Paradoxical breathing chest wall motion
paralysis of intercostals
* chest moves in secondary to loss of motor function and negative intrathoracic cavity pressure
72
normal breathing - inspiration
Active (work done by diaphragm and ICs
73
normal breathing - Expiration
*Passive at rest (work done by elastic recoil of lung
74
when does paradoxical breathing pattern occur
paraplegia
75
Rib movement in breathing:
* Upper ribs (3-6) move in “pump handle” motion
* Lower ribs (7-10) move with “bucket handle motion
76
any disease that restricts rib movement affects ....
ventilation (restrictive lung disease)
77
Kyphoscoliosis (severe kyphosis)
causes ribs to approximate each other decreasing excursion
*affects more males than females
78
scoliosis
ribs on convex side of bend diverge while ribs on concave side approximate each other
79
minute ventilation
- volume moved through the lung/min
- Vmin = Vt x RR
- for given Vmin, patients with decreased TV, must breathe at a faster rate
80
dead space (anatomic)
- the portion of gas in the lung not in contact with blood (that part that does not participate in gas exchange)
- Vd = about 150 ml in a normal healthy adult
- for a person breathing at a higher RR, dead air/min is increased (wasted effort and increased work of breathing)
81
primary muscles of respiration
Diaphragm
* External Intercostals: run diagonally inferior and
anterior --> probably inspiration
* Internal Intercostals: run diagonally inferior and
posterior --> Fx- probably inspiration
* Innermost Intercostals: same as internal
82
excursion of diaphragm in varying body positions:
– Supine: expiratory excursion is greatest
- Moves further into thoracic cavity
– Standing and side lying: intermediate excursion.
– Sitting: minimal excursion
83
quiet breathing
diaphragm moves 2/3 inch
84
maximal breathing
2.5-4 inches
85
Accessory Muscles of Respiration
* Sternocleidomastoid
* Scaleni
* Trapezius:(upper only)
* Pectoralis Major & Minor
* Serratus Anterior
* Latissimus Dorsi
* Serratus Posterior/ Superior
* Quadratus Lumborum
* Iliocostalis
86
Scaleni
– anterior: attaches to 1st rib
– middle: attaches to 1st rib
– posterior: attaches to 2-3 rib
87
Number of pulmonary arteries and veins
fixed at birth at level of terminal respiratory units
88
Number of arterioles and venules in respiratory units
increase with age, parallel with addition of new RUs
89
what is pulmonary artery pressure at birth?
- high
- declines over next 4 months
- if pressure remains high, artery wall changes
90
pulmonary capillaries
very fine network of branches capillaries
91
where are pulmonary capillaries located
in the septa and walls of alveoli
92
what do pulmonary veins serve as?
a reservoir for LV, negating the pulsatile flow of the RV and changes in flow with inspiration/expiration.
93
Pulm. A & Vs parallel branching of bronchi to the
level of the segments:
veins run between segments and multiple veins drain each segment
94
Bronchial circulation
* One R-bronchial artery, 2 L-bronchial arteries
* Accompany branching of the bronchi down to the level of the terminal bronchioles
* Bronchial arteries receive 1-2% of the CO
95
function of bronchial circulation
to maintain blood supply in the event of pulmonary embolism
96
Static Lung Volumes
* Tidal Volume (VT)
* Inspiratory Reserve Volume (IRV)
* Expiratory Reserve Volume (ERV)
* Residual Volume (RV)
* Inspiratory Capacity (IC)
* Functional Residual Capacity
* Vital Capacity (VC)
* Total Lung Capacity (TLC), ERV - RV
97
dynamic lung:
volumes/rates
98
PEF
peak expiratory flow
99
FVC
forced vital capacity
100
FEV1
forced expiratory volume in 1 second
101
FER
FEV1/FVC ratio
102
what is COPD
Class of diseases of respiratory tract caused by
obstruction of the airways
103
COPD signs and symptoms
cough, dyspnea on exertion, wheezing expectoration of mucus
104
diagnosis of COPD
- based on pulmonary function tests
– expiratory flow rate limited
– residual volume increased
* Hyperinflated lung: exhalation affected
– Also: increased mucus production, inflammation of mucosal lining, mucosal thickening, bronchiolar
muscle spasm
105
COPD includes:
- bronchopulmonary dysplasia
- cystic fibrosis
- asthma
- bronchiectasis
- chronic bronchitis
- emphysema
106
bronchopulmonary dysplasia
fibrotic changes in lung of infant secondary to ventilation
107
cystic fibrosis
excessive mucus production
108
asthma
airway hyper-responsiveness to allergens/irritants
109
bronchiectasis
dilation/distortion of bronchi secondary to infection
110
chronic bronchitis
excessive production of mucus secondary to smoking
111
emphysema
enlargement of terminal sacs, destruction of alveolar walls & septa, loss of elastic tissue
112
look at the little pulmonary function testing on 25
113
type A COPD - chronic emphysema
– SOB
– Little sputum production
– Barrel shaped chest w flat diaphragm & horizontal ribs
– Hypertrophied accessory muscles of
respiration & use of posturing
– Rapid, shallow breathing
– Due to hypercapnia, patients with light complexion may appear paradoxically pinkish
114
type B COPD
* productive cough
* Over-weight
* cyanosis
* associated w/ heart failure and peripheral edema
115
restrictive lung disease
an abnormal reduction in pulmonary ventilation with diminished expansion of the lungs
116
causes of restrictive lung disease
trauma, radiation Rx, rib or spinal deformity or secondary to primary lung disease
117
compliance =
change in V/change in P
118
compliance in restrictive lung disease
- compliance of either or both chest wall and lungs are decreased
- This results in a stiffer lung which is more difficult to open at any given volume, but especially at high lung volumes when C is minimal already
119
lung volume in restrictive lung disease
Because the distensibility of the lung is
decreased, all lung volumes are affected:
– Inspiratory reserve volume: decreased
– VT -initially preserved, but in time decreases
– Expiratory reserve volume: decreased, but especially affected by RLD that is caused by a decrease in lung, not chest wall, compliance.
– Residual Volume: decreased
– TLC and vital capacity also decreased
120
clinical manifestations of restrictive lung disease
tachypnea, alveolar hyperventilation, ventilation perfusion mismatching, crackles, decreased diffusing capacity, cor pulmonary
121
RLD- tachypnea
increased rate secondary to decreased volume
122
RLD- hyperventilation
overcompensation
123
RLD- ventilation perfusion mismatching
hypoxemia
124
RLD- crackles
secondary to atelectatic alveoli opening
125
RLD- decreased diffusing capacity
widening of interstitial space due to scar tissue , stretching
126
RLD- cor pulmonary
- pulmonary arterial HTN secondary to hypoxemia, fibrosis, compression of pulm. capillaries
- may lead to R-side HF, decreased exercise tolerance
127
RDL symptoms
* Dyspnea/SOB (initially w/exercise, but later at rest)
* Irritating, dry and unproductive cough --> secondary to irritation from increased velocity of air movement across airways
* Muscle wasting/cachectic look --> secondary to the increased work of breathing
* Difficulty eating secondary to increased work of breathing --> decreased appetite
* Acute and chronic cyanosis --> Clubbing of nails (chronic cyanosis), Bluish discoloration of nail beds and mucosa
128
clubbing of the nails
- broadening of distal phalanges with down-ward angulation and rounding of the nail
- Common with restrictive lung disease, but may also happen with COPD
